Save the cookies for another day and make bars, which involve just one pan and can be sliced as large or small as you need (these recipes serve as many as 100!).

By Lynn Andriani

Photo: Rachel Been

1 of 8

The Last-Minute Chocolate-Hazelnut Squares

Liz Gutman and Jen King, proprietors of the Brooklyn sweet shop Liddabit Sweets and authors of The Liddabit Sweets Candy Cookbook, say the active work time to make the filling for these squares—made of chocolate, Nutella and cereal flakes—is about three minutes. That makes them the perfect eleventh-hour lifeline for when you remember you need a dessert for tomorrow's potluck. Bonus: The recipe makes about 100 one-inch squares.